oracle 如何将数据类型 CLOB 更改为 VARCHAR2(sql)
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How to change a dataype CLOB TO VARCHAR2(sql)
提问by PHPnoob
Table: customers
表：客户
ID NAME DATATYPE
NUMBER VARCHAR2(100) CLOB
I want to change the DATAcolumn from CLOBto `VARCHAR2(1000)
我想将DATA列从更改CLOB为 `VARCHAR2(1000)
I have try ALTER TABLE customers MODIFY DATA VARCHAR2 (1000)also
我尝试ALTER TABLE customers MODIFY DATA VARCHAR2 (1000)也
ALTER TABLE customers MODIFY (DATA VARCHAR2 (1000))
ALTER TABLE customers MODIFY (DATA VARCHAR2 (1000))
also
还
alter table customers modify
(data VARCHAR2(4000))
those normally works if the datatype is not a clob but I am getting a ORA-22859because I am using oracle toad/apex.
如果数据类型不是clob，这些通常有效，但我得到一个，ORA-22859因为我使用的是oracle toad/apex。
回答by Rahul Tripathi
You may try this:
你可以试试这个：
Add a new column as varchar2
alter table my_table add (new_column varchar2(1000));UPDATE CLOB name to varchar2 column;
update my_table set new_column=dbms_lob.substr(old_column,1000,1);
添加一个新列作为 varchar2
alter table my_table add (new_column varchar2(1000));将 CLOB 名称更新为 varchar2 列；
update my_table set new_column=dbms_lob.substr(old_column,1000,1);
After testing your data:
经过测试数据：
DROP CLOB column
alter table my_table drop column old_columnRename varchar2 column to CLOB column name
alter table my_table rename column new_column to old_column
删除 CLOB 列
alter table my_table drop column old_column将 varchar2 列重命名为 CLOB 列名
alter table my_table rename column new_column to old_column
